Biancaea Tod., Nuovi Gen. Sp. Orto Palermo: 21. 1860, descr. emended E. Gagnon & G. P. Lewis

Gagnon, Edeline, Bruneau, Anne, Hughes, Colin E., de Queiroz, Luciano Paganucci & Lewis, Gwilym P., 2016, A new generic system for the pantropical Caesalpinia group (Leguminosae), PhytoKeys 71, pp. 1-160 : 44-46

publication ID

https://dx.doi.org/10.3897/phytokeys.71.9203

persistent identifier

https://treatment.plazi.org/id/595ED69A-D48B-5715-8BBD-8087D3965881

treatment provided by

PhytoKeys by Pensoft

scientific name

Biancaea Tod., Nuovi Gen. Sp. Orto Palermo: 21. 1860, descr. emended E. Gagnon & G. P. Lewis
status

 

13. Biancaea Tod., Nuovi Gen. Sp. Orto Palermo: 21. 1860, descr. emended E. Gagnon & G. P. Lewis Figs 20G-J View Figure 20 , 22 View Figure 22

Campecia Adans. 1763; no type species designated, and no species names ever published in this genus. It is thus not possible to apply this name which is rejected against Biancaea .

Caesalpinia sect. Sappania DC. 1825.

Diagnosis.

Biancaea is closely related to Mezoneuron , differing principally in its fruit, a coriaceous, laterally compressed, wingless, dehiscent pod (except Biancaea decapetala , which has somewhat inflated, boat-shaped pods, often with a narrow wing or ridge along the upper suture). In contrast, Mezoneuron has chartaceous, coriaceous or ligneous pods, which are also laterally compressed, but indehiscent, and with a wing along the upper suture. In addition, the ovary of Biancaea species always has a velvety indumentum (vs. glabrous to pubescent in Mezoneuron ).

Type.

Biancaea scandens Tod. ≡ Biancaea decapetala (Roth) Deg.

Emended description.

Lianas, climbing or trailing shrubs (1-3 m), or small trees (2.5-10 m), armed with short, slightly recurved prickles, scattered along the branches; young shoots pubescent or glabrescent. Stipules lanceolate-oblong to broadly-ovate, sometimes amplexicaul at base, 3-4 mm to 4.5 cm long, caducous or sub-persistent to persistent. Leaves alternate (except in Biancaea oppositifolia ), bipinnate, ending with a pair of pinnae, rachis pubescent (glabrous in Biancaea oppositifolia ), armed with pairs of prickles at the base of each pinna, sometimes also scattered on the rachis; pinnae in 4-19 opposite to alternate pairs; leaflets opposite to alternate, in 5-20 pairs per pinna, blade membranous, eglandular, glabrous to pubescent, 10-35 × 4-15 mm (4-10 × 1.5-4.5 cm in Biancaea oppositifolia ), oblong-elliptic, apex acute, obtuse, rounded to emarginate, base asymmetric. Inflorescences erect, showy, terminal or axillary racemes or panicles; rachis eglandular, pubescent, unarmed or with a few scattered prickles, mainly near the base; bracts ovate-lanceolate, acuminate, 2-8 mm long, caducous. Flowers bisexual, zygomorphic; calyx with a short hypanthium and 5 sepals, the lower sepal cucullate and covering the other 4 in bud, sepals pubescent (except in Biancaea sappan ), caducous, but the hypanthium persisting as a calyx ring around the pedicel as fruits mature; petals 5, free, yellow to white, eglandular, the claws pubescent; the median petal smaller than the other 4, and inrolled towards the centre, lateral petals oblong, obovate to spathulate, 4-10 × 2-8 mm; stamens 10, filaments densely pubescent (most evident at the base), eglandular, 10-15 mm long; ovary densely velutinous. Fruit a coriaceous, glabrous, eglandular, oblong-elliptic to obovate, dehiscent, wingless, laterally compressed (but somewhat inflated and often with a narrow wing along the upper suture in Biancaea decaptala ), 4.5-10 × 2-4 cm, 2-8-seeded pod, usually much broader at the rounded to truncate apex, which terminates in a sharp beak. Seeds flat, elliptic, ovoid to orbicular, c. 2 cm in diameter, black or brown.

Geographic distribution.

A genus of six species widespread across southern Asia, from India, to Myanmar (Burma), Thailand, Cambodia, Vietnam, south China, Japan, the Philippines, and the Malay Peninsula and Archipelago, one species endemic to Sabah (near Sandakan). Biancaea decapetala , native to Asia, has been widely introduced across the tropics as a hedge plant or ornamental and is considered to be invasive in South Africa and Hawaii.

Habitat.

Primary forest and forest margins, grasslands, scrub vegetation, riverine habitats, secondary thickets and clearings. From the coast to mountain slopes.

Etymology.

Unknown.

Notes.

Based on the study of Gagnon et al. (2013), Molinari-Novoa et al. (2016) provided some, but not all, of the required nomenclatural transfers to the genus Biancaea . Furthermore, they did not emend the description of the genus, as provided here.

References.

Hattink (1974); Vidal and Hul Thol (1976); Jansen (2005); Brummitt et al. (2007); Chen et al. (2010a); Molinari-Novoa et al. (2016).

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Fabales

Family

Leguminosae

Loc

Biancaea Tod., Nuovi Gen. Sp. Orto Palermo: 21. 1860, descr. emended E. Gagnon & G. P. Lewis

Gagnon, Edeline, Bruneau, Anne, Hughes, Colin E., de Queiroz, Luciano Paganucci & Lewis, Gwilym P. 2016
2016
Loc

Campecia

Adanson 1763
1763